In security installations there is often a need for a sound generator such as a horn or siren to provide an audible indication of an alarm condition. Horn sounders are usually of the electromechanical type which requires substantial power for energization. Electronic sound generators are also known for providing continuous or siren sounds but such devices also require relatively high power to provide a suitably intense sound level. It is known that the use of a sound generator employing two frequencies and providing a beat note in addition to the primary frequencies produces a sound which is more readily perceived by an individual because of the harsh or annoying nature of the sound. Many automobile horns operate in this manner. It is an object of this invention to provide an electronic sounder which operates with very low power to generate a loud raucous sound and which can be constructed in an extremely compact package at very low cost.